Chapter 13

Ion-dipole forces

An ionic solute in a polar solvent

Hydrogen bonding

CH3OH in H2O

Dispersion forces

Choice, I2 in hexane (C6H14) I2 in hexane (C6H14)

Which of the following statements correctly describe solutions consisting of gases and/or solids? Select all that apply.

Gas-gas solutions form readily because all gases are miscible with each other. Gas-solid solutions are important as catalysts. A gas may dissolve in a solid by occupying the spaces between the solid particles.

Which of the following is an intermolecular force exhibited in a solution of CH3OCH3 in CH3OH? Select all that apply. Multiple select question.

Hydrogen bonding Dispersion forces Dipole-dipole forces

Which of the following intermolecular forces help to stabilize a DNA double helix? Select all that apply. Multiple select question.

Ion-dipole forces Dispersion forces Hydrogen bonds

Ion-dipole

NaCl in CH3CH2OH

______ alcohols are more soluble in water and ______ alcohols are more soluble in nonpolar solvents like hexane. Multiple choice question.

Small;large

Which of the following options describe situations in which hydrogen bonding will be observed between the solute and the solvent? Select all that apply. Multiple select question.

Solvent and solute both contain OH or NH groups. Solvent contains OH or NH groups, solute contains N, O, or F atoms. Solvent contains N, O, or F; solute contains OH or NH groups.

Dipole-induced dipole forces

a nonpolar solute in a polar solvent

Ion-induced dipole forces

a nonpolar solute in a polar solvent that also contains dissolved ions

Which of the following statements correctly describe solubility? Select all that apply.

A concentrated solution contains a relatively large amount of solute in a given amount of solvent. The solubility of a given substance in a particular solvent varies with temperature.

Both soaps and cell membranes rely on the behavior of molecules with dual polarity. Which of the following statements correctly describe this behavior? Select all that apply.

A soap functions because the nonpolar "tails" of the molecules bond to grease and the polar "heads" carry the grease into the solvent. The lipid molecules that make up a cell membrane have a nonpolar hydrocarbon portion and a polar-ionic "head." A cell membrane maximizes contact between parts of the lipid molecules that have the most similar types of intermolecular forces.

Certain substances such as alcohols are able to dissolve fairly readily in both polar and nonpolar solvents. Which statements correctly explain this behavior? Select all that apply.

Alcohols have dual polarity since they possess a polar OH group as well as a nonpolar hydrocarbon portion. Alcohols form strong interactions with both types of solvent. The hydrocarbon portion of the alcohol interacts with the nonpolar solvent through dispersion forces.

Which of the following statements correctly describe the effect of alcohol structure on solubility? Select all that apply.

As the hydrocarbon chain increases in length, the alcohol becomes less soluble in polar solvents. Smaller alcohols are more soluble in H2O than larger alcohols.

Which of the following statements correctly describe the molality and molarity of a solution? Select all that apply.

Both molarity and molality express concentration in terms of moles of solute. For a dilute aqueous solution molality and molarity are nearly equal. M must be calculated using the volume of the solution, not the volume of the solvent.

Attractions between nonpolar side chains in the protein's interior

Dispersion forces

Helical and sheet-like arguments

H bonds between C--O of one peptide bonds

A solution is a _____ mixture, meaning it exists in one phase, whereas a colloid is a _____ mixture with two or more phases in its composition. Multiple choice question.

Homogenous; Hetrogeneous

Protruding side chains into the surrounding cell fluid

Ion-dipole forces and H bonds

Dipole-induced dipole

O2 (g) in aqueous solution

Dispersion forces

Present in all solutions; principal intermolecular force when both solvent and solute are present

What does the term "like dissolves like" mean? Multiple choice question.

Substances that have similar types of intermolecular forces dissolve in each other.

Which of the following statements correctly describe different types of mixtures? Select all that apply

The composition of any mixture is variable. A heterogeneous mixture contains two or more different phases. Differences in particle size account for the main differences between solutions and colloids.

Will HCl (g) or NaCl (s) be more soluble in the solvent CH3OCH3? Why? Multiple select question.

The dipole-dipole forces in an HCl solution are similar in strength to the dipole-dipole forces between CH3OCH3 molecules. HCl (g) will be more soluble in CH3OCH3.

Which of the following statements correctly describes the action of Gramicidin A and similar antibiotics? Select all that apply. Multiple select question.

These antibiotics form channels in the cell membrane of the bacterium. Vast numbers of ions pass through the antibiotic per second. The polar interiors of these antibiotics pass along ions using ion-dipole forces.

Which of the following options correctly describe the different ways of expressing the concentration of a solution? Select all that apply. Multiple select question.

To calculate mole fraction for a given mass of a reactant or product, the masses of all solution components must be known. The unit for molality (symbol m) is mol/kg.

I2 (s) has a very low solubility in H2O (l) because the weak _____ forces between I2 and H2O are not strong enough to replace the _____ between the H2O molecules.

dipole-induced dipole; hydrogen bonds

The ratio mol of soluteL of solutionmol of soluteL of solution is called the _____ of a solution (symbol M), whereas the _____ (symbol m) of the solution is expressed as mol of solutekg of solventmol of solutekg of solvent. For an aqueous solution, these two quantities will be very similar if the solution concentration is _____. Multiple choice question.

molarity; molality; low

The function of a soap molecule arises from its dual polarity. Its ______ interacts with grease while its ______ interacts with a solvent like water to wash the grease away.

nonpolar "tail"; polar "head"